I. Field of the Invention
The present invention relates generally to sensor amplifier circuits.
II. Description of Related Art
During the evaluation, design, and testing of electronic circuits, many types of different sensors are utilized. Especially, electrical/optical sensors, magnetic/optical sensors, and loop antenna current sensors are all useful devices for the development and investigation of electromagnetic capability as well as signal/power integrity for many types of electronics.
These sensors utilize a photo sensor to detect a signal from the device under test. Furthermore, such sensors require both a wideband and low noise amplifier in order to test high frequency circuits with high accuracy.
One disadvantage of these sensors, and particularly photo sensors, is that the sensor exhibits stray capacitance which is coupled to the input of the amplifier. This stray capacitance not only reduces bandwidth of the amplifier output, but also increases the noise in the amplifier output. Such decreased bandwidth and increased noise inhibit accurate readings during the test or evaluation.